Generally, a process for manufacturing semiconductor products includes forming, on a pure silicon wafer, a semiconductor chip, packaging the semiconductor chip so as to protect same from external environments while allowing same to electrically communicate with an external device, and testing the packaged semiconductor product.
The step of manufacturing a semiconductor chip includes a sub-step of applying a photoresist of a certain thickness on a wafer surface and performing thereto an exposure and develop process using a mask with a certain pattern, thereby selectively forming a specific pattern on the wafer, and a sub-step of implanting impurity ions into a portion removed according to the specific pattern of the photoresist to form a characteristic thin film.
Herein, equipment for applying a photoresist on a wafer surface is called a spin coater, which as shown in FIG. 1, includes a spin chuck 1 for rotating the wafer W at high speed while safely seating the same, and a spray nozzle 2 for spraying the photoresist on the surface of the wafer W.
Meanwhile, the photoresist applied on the wafer surface by the spin coating is formed, because of centrifugal force, such that the thickness thereof at the edge of the wafer is thicker or more irregular than that at the center portion of the wafer. Furthermore, the photoresist is applied and agglomerated even at a portion of the back surface of the wafer to form an edge bead.
Such an edge bead may contact and collide against a cassette and the like causing the edge bead to break into pieces, which operate as particles during a subsequent process. Thus, before the exposure process, an edge bead removal (EBR) process for removing an edge bead should be performed.
As illustrated in FIG. 1, an EBR apparatus is provided with a side rinse nozzle 3 in the spin coater, and the nozzle tip is positioned toward the edge of the wafer, as shown. A cleaning solution is sprayed through the side rinse nozzle 3. The side rinse nozzle 3 is movably supported by a support arm 4.
The side rinse nozzle 3 as disclosed in Korean Patent publication No. 0215886 and Korean Laid-open Publication No. 2001-0029163 is formed in one unit so that with the operation of the support arm 4, it is positioned outside of process equipment and, after the completion of the application of the photoresist, moved inside of process equipment so that the nozzle tip is positioned at the edge of a wafer, thereby supplying the cleaning solution, such as a thinner, to the edge of rotating wafer W to remove the photoresist from the edge.
The uses of a plurality of strip nozzles are disclosed in U.S. Pat. Nos. 6,516,815 and 6,691,719 and Japanese Laid-open Publication No. 204-179211.
Unfortunately, conventional side rinse nozzles that spray cleaning solution can require excessive time to remove edge beads. Moreover, extended spray time can damage important patterns of a wafer. In addition, conventional side rinse nozzles that spray cleaning solution may not adequately remove edge beads.